During traveling of a vehicle, a desired motion control is carried out by controlling each device capable of controlling a traveling state of a vehicle while detecting and estimating a state amount of a vehicle in a vehicle where a quantity of motion of the vehicle is controlled according to the traveling state. For example, in a vehicle active suspension described in Patent Literature 1, the position control of the vehicle is carried out based on a control amount, which corresponds to an actual lateral acceleration detected from a lateral G sensor, and a control amount, which corresponds to a calculated lateral acceleration predicted based on outputs of a steering angle sensor and a vehicle speed sensor.
The vehicle active suspension stops the use of the calculated lateral acceleration when detecting that the vehicle is in a side slipping state to suppress a state in which the position control is carried out using the calculated lateral acceleration, which is beyond the actual vehicle body behavior, at the time of occurrence of side slipping from being obtained. Furthermore, if determined that a difference between the calculated lateral acceleration and the actual lateral acceleration is not greater than or equal to a predetermined value, the determination on the difference between the calculated lateral acceleration and the actual lateral acceleration is again repeated after elapse of a predetermined time. The undesired roll thus can be suppressed from occurring.